This invention pertains to metal working machines and more particularly to an improved metal working machine which is able to shear sheet metal, bend sheet metal, punch sheet metal and metal plate as well as shear angle extrusions.
An operator of a metal fabrication shop must procure a number of machines to perform various metal fabrication operations. Such operations include break forming, shearing and punching. In a break forming operation, a sheet metal workpiece is positioned between two corresponding male and female dies that are brought together to form a bend in the workpiece. In a shearing operation, a sheet metal workpiece is placed between blades that are brought together to shear the workpiece. Preferably, in a shearing operation, the blades meet at a slight angle so that only a portion of the workpiece is sheared at any given time. Extruded angles may be cut using an angle shear which generally includes an cutter portion and an anvil portion. A punch press having a punch tool and an anvil can be used to punch holes in sheet or plate workpeices.
Conventional multiple operation metal working machines are known as xe2x80x9ciron workersxe2x80x9d. Iron workers typically can perform several operations in one machine. Malmgren, in U.S. Pat. No. 3,701,276 teaches an iron and metal working machine having a main beam that pivots to operate a punch press at one end and a sheet metal sheer and other selected metal working accessories at the opposite end. However, Malgren""s machine, like many metal working machines of its type, has a configuration that prevents an operator from processing relatively large workpieces. Moreover, because of the configuration of prior art metal working machines such as the machine taught by Malgren, it is not possible to independently execute operations at opposite ends of the main beam. With prior art metal working machines, only one operation may be performed by one operator at any given type.
Thus, there has been a need in the metal working industry for a metal working machine that has a greater degree of versatility in performing operations on a larger range of workpieces and which can also be operated simultaneously by more than one operator to perform separate metal working tasks.
Accordingly, the principle object of the present invention is to provide a machine that includes a moving frame that moves in relation to a stationary frame so that metal working dies attached to the moving frame can be translated at both ends of the moving frame either simultaneously or independently. Another object of the present invention is to provide a machine that has opposite dies of a break form tool fixed to corresponding portions of the moving frame and the stationary frame so that as one end of the moving frame is translated by a greater distance than the other end of the moving frame, a contoured bend having a gradually increasing angle of bend along the length of the bend can be formed into a sheet metal workpiece. Yet another object of the present invention is to provide a machine that has opposing sheet metal shearing blades fixed to corresponding portions of the moving frame and the stationary frame so that both ends of the moving frame are translated together, a relatively large sheet metal workpiece may be cut across a distance that is a large portion of the width of the moving frame. Still yet another object of the present invention is to provide a machine having opposing sheet metal shearing blades fixed to the moving frame and the stationary frame so that as only one end of the moving frame is translated, a relatively small sheet metal workpiece may be cut at a location adjacent to the portion of the moving frame that is moving. Finally, it is an object of the present invention to provide metal working tools each having a moving die and a stationary die such as a punch press for punching holes in plate or a shear for cutting metallic extrusions where the moving die of a particular tool is fixed to the moving frame at one end of the moving frame and the stationary die is fixed to the stationary frame at the same end so that as the same end of the moving frame is translated, the moving die attached to that end of the moving frame moves in relation to its corresponding stationary die to perform an operation only at the moving end of the moving frame.
These and other objects of the invention are attained in an improved metal working machine that performs multiple operations. The invention metal working machine includes a stationary frame and a moving frame. Both the stationary frame and the moving frame carry opposite corresponding tool dies that perform metal working operations when the moving frame translates relative to the stationary frame. The stationary frame is a rigid, rectangular structure having two spaced columns and at least two horizontal beams connecting the spaced columns. The moving frame is a non-rigid pinned rectangular structure having two vertical members that are connected together at pinned joints by two horizontal beams. The moving frame is arranged so that one end can move while the other end remains stationary. When only one end of the moving frame is translated, the moving frame transforms from a rectangle to a parallelogram. The horizontal beams of the moving frame engage the columns of the stationary frame so that they can slide up and down relative to the columns of the stationary frame. The vertical members of the horizontal frame are positioned next to the columns of the stationary frame and slide along paths that are parallel to the columns of the stationary frame. Hydraulic cylinders on each end of the metal working machine are connected by pivot joints between the stationary frame and moving frame. When both of the hydraulic cylinders are activated in the same direction, the entire moving frame moves up or down relative to the stationary frame. If only one of the hydraulic cylinders is activated, only one side of the moving frame translates while the other side of the moving frame moves only slightly as it pivots about the pivot joint connecting it to the hydraulic cylinder which is not activated.
The horizontal members of the moving frame and the horizontal members of the stationary frame carry corresponding tool dies. Corresponding sheet metal cutting blades are attached to horizontal beams of the stationary frame and the moving frame so that when the moving frame translates the cutting blades pass each other to cut a workpiece. In the same way, a male break forming die is mounted to a horizontal member of the moving frame and a corresponding female break forming die is mounted to a horizontal beam of the stationary frame. When the moving frame translates, a sheet metal workpiece may be formed between the break forming dies.
Other metal working tools such as a shear for cutting extruded angles or a punch for punching holes In sheet or plate material can be mounted to adjacent portions of the left or right side of the stationary frame and the moving frame. Because these other metal working tools are mounted on the left or right side of the machine, a tool or set of tools on one side may be operated independently as only that side is translated.